[¦yü·nə‚fȯrm·lē ‚nän‚skwer ′bä‚näk ′spās] (mathematics) A Banach space for which there is a positive number ε such that there are no nonzero elements, x and y, that have the same norm and satisfy the inequalities │ x + y │ > (2 - ε) │ x │ and │ x-y │ > (2 - ε) │ x │.